The habenular nucleus （Hb） is an important structure that regulates the function of the pineal gland which may affect melatonin content in the pineal gland after sleep deprivation （SD）. In the present study, high ...The habenular nucleus （Hb） is an important structure that regulates the function of the pineal gland which may affect melatonin content in the pineal gland after sleep deprivation （SD）. In the present study, high performance liquid chromatography showed that the melatonin content in the pineal gland was significantly reduced, and y-aminobutyric acid content in the Hb was significantly increased after SD. Furthermore, the melatonin content in the pineal gland was markedly reduced after Hb lesion under normal sleep and SD conditions. Immunohistochemistry showed that the number of Fos-positive neurons was significantly decreased in the lateral and medial Hb after SD. The findings demonstrate that the reduction of melatonin in the pineal gland after SD is related to decreased activity of Hb neurons, and that the Hb can regulate sleep-wake rhythm by influencing melatonin secretion in the pineal gland.展开更多
BACKGROUND:Melatonin (N-acetyl-5-methoxytripta-mine) is a free radical scavenger and a strong antioxidant,secreted by the pineal gland.In this study,we evaluated the effects of decreasing and increasing serum melatoni...BACKGROUND:Melatonin (N-acetyl-5-methoxytripta-mine) is a free radical scavenger and a strong antioxidant,secreted by the pineal gland.In this study,we evaluated the effects of decreasing and increasing serum melatonin levels on malonyldialdehyde (MDA),superoxide dismutase (SOD),and reduced glutathione (GSH) levels in pancreatic tissue from rats with experimental acute pancreatitis.METHODS:Experimental acute pancreatitis was induced in three groups of Wistar albino rats (10 animals per group) by pancreatic ductal ligation.The first group had only acute pancreatitis and served as the control.Surgical pinealectomy was added to acute pancreatitis in the second group,removing the source of endogenous melatonin (low melatonin levels group).The third group was given 0.1 ml daily intraperitoneal injections of 20 mg/ml melatonin solution for one week (high melatonin levels group).The effects of melatonin levels were evaluated by comparison of the levels of MDA,SOD,and GS in pancreatic tissue.RESULT:We found that intraperitoneal melatonin injections decreased the levels of MDA and increased the levels of SOD and GSH in pancreatic tissue.CONCLUSION:Exogenous melatonin has a preventive effect on lipid peroxidation and oxidative damage in acute pancreatitis.展开更多
Objective To further authenticate the role of melatonin on endogenous biologic clock system.Methods Pinealectomized mice were used in the experiments,a series of circadian rhythm of physiology index,such as glucocorti...Objective To further authenticate the role of melatonin on endogenous biologic clock system.Methods Pinealectomized mice were used in the experiments,a series of circadian rhythm of physiology index,such as glucocorticoid,amino acid neurotransmitter,immune function,sensitivity of algesia and body temperature were measured.Results Effects of melatonin on endogenous circadian rhythm roughly appeared four forms:1)The model of inherent rhythm was invariant,but midvalue was removed.2)Pacing function:pinealectomy and melatonin administration changed amplitude of the circadian vibration of aspartate,peripheral blood WBC and serum hemolysin.3)Phase of rhythm changed,such as the effects on percentage of lymphocyte and sensitivity of algesia.4)No effect,the circadian rhythm of body temperature belong to this form.Conclusions Melatonin has effects some circadian rhythm,and it can adjust endogenous inherent rhythm and make the rhythm keep step with environmental cycle.Melatonin may be a kind of Zeitgeber,Pineal gland might being a rhythm bearing organ to some circadian rhythm.展开更多
A flow-injection chemiluminescence （CL） method for the determination of melatonin based on the CL reaction of melatonin with hydrogen peroxide and sodium hypochlorite （NaOCl） in a basic alkaline solution was devel...A flow-injection chemiluminescence （CL） method for the determination of melatonin based on the CL reaction of melatonin with hydrogen peroxide and sodium hypochlorite （NaOCl） in a basic alkaline solution was developed. The possible CL mechanism has been discussed, and a proposal for the reaction pathway was given that singlet oxygen was clarified to be produced in this reaction system and was responsible for the CL emission. Under the optimized conditions, the linear concentration range of application was 1.0×10^-7-2.5 × 10^-4 moloL-I with a de- tection limit of 5.0 ×10^-8 moloL-1 （S/N= 3）. The relative standard deviation for eight repeated measurements of 1.0×10^-6 mol·L^-1 melatonin was 2.8%. The interferences of several important biological substances, some indole compound, cations and anions were studied. No interference was found for the anions, glucose, starch, most of cations and low concentration （less than 3.0 × 10^-6 mol·L^-1） of some biological substances and indole compound. The method was applied to the determination of melatonin in rat pineal gland and drug with satisfactory results. The sample throughput was 90 injections per hour.展开更多
基金the National Natural Science Foundation of China, No. 30970956, 30570579
文摘The habenular nucleus （Hb） is an important structure that regulates the function of the pineal gland which may affect melatonin content in the pineal gland after sleep deprivation （SD）. In the present study, high performance liquid chromatography showed that the melatonin content in the pineal gland was significantly reduced, and y-aminobutyric acid content in the Hb was significantly increased after SD. Furthermore, the melatonin content in the pineal gland was markedly reduced after Hb lesion under normal sleep and SD conditions. Immunohistochemistry showed that the number of Fos-positive neurons was significantly decreased in the lateral and medial Hb after SD. The findings demonstrate that the reduction of melatonin in the pineal gland after SD is related to decreased activity of Hb neurons, and that the Hb can regulate sleep-wake rhythm by influencing melatonin secretion in the pineal gland.
文摘BACKGROUND:Melatonin (N-acetyl-5-methoxytripta-mine) is a free radical scavenger and a strong antioxidant,secreted by the pineal gland.In this study,we evaluated the effects of decreasing and increasing serum melatonin levels on malonyldialdehyde (MDA),superoxide dismutase (SOD),and reduced glutathione (GSH) levels in pancreatic tissue from rats with experimental acute pancreatitis.METHODS:Experimental acute pancreatitis was induced in three groups of Wistar albino rats (10 animals per group) by pancreatic ductal ligation.The first group had only acute pancreatitis and served as the control.Surgical pinealectomy was added to acute pancreatitis in the second group,removing the source of endogenous melatonin (low melatonin levels group).The third group was given 0.1 ml daily intraperitoneal injections of 20 mg/ml melatonin solution for one week (high melatonin levels group).The effects of melatonin levels were evaluated by comparison of the levels of MDA,SOD,and GS in pancreatic tissue.RESULT:We found that intraperitoneal melatonin injections decreased the levels of MDA and increased the levels of SOD and GSH in pancreatic tissue.CONCLUSION:Exogenous melatonin has a preventive effect on lipid peroxidation and oxidative damage in acute pancreatitis.
文摘Objective To further authenticate the role of melatonin on endogenous biologic clock system.Methods Pinealectomized mice were used in the experiments,a series of circadian rhythm of physiology index,such as glucocorticoid,amino acid neurotransmitter,immune function,sensitivity of algesia and body temperature were measured.Results Effects of melatonin on endogenous circadian rhythm roughly appeared four forms:1)The model of inherent rhythm was invariant,but midvalue was removed.2)Pacing function:pinealectomy and melatonin administration changed amplitude of the circadian vibration of aspartate,peripheral blood WBC and serum hemolysin.3)Phase of rhythm changed,such as the effects on percentage of lymphocyte and sensitivity of algesia.4)No effect,the circadian rhythm of body temperature belong to this form.Conclusions Melatonin has effects some circadian rhythm,and it can adjust endogenous inherent rhythm and make the rhythm keep step with environmental cycle.Melatonin may be a kind of Zeitgeber,Pineal gland might being a rhythm bearing organ to some circadian rhythm.
基金Project supported by the National Natural Science Foundation of China （No. 20437020） and Zhaoqing Innovative Research Program.
文摘A flow-injection chemiluminescence （CL） method for the determination of melatonin based on the CL reaction of melatonin with hydrogen peroxide and sodium hypochlorite （NaOCl） in a basic alkaline solution was developed. The possible CL mechanism has been discussed, and a proposal for the reaction pathway was given that singlet oxygen was clarified to be produced in this reaction system and was responsible for the CL emission. Under the optimized conditions, the linear concentration range of application was 1.0×10^-7-2.5 × 10^-4 moloL-I with a de- tection limit of 5.0 ×10^-8 moloL-1 （S/N= 3）. The relative standard deviation for eight repeated measurements of 1.0×10^-6 mol·L^-1 melatonin was 2.8%. The interferences of several important biological substances, some indole compound, cations and anions were studied. No interference was found for the anions, glucose, starch, most of cations and low concentration （less than 3.0 × 10^-6 mol·L^-1） of some biological substances and indole compound. The method was applied to the determination of melatonin in rat pineal gland and drug with satisfactory results. The sample throughput was 90 injections per hour.
